Claim Terms Issue in GST

Did all the setups as per GST Note,

1) Created AP Manual invoice, attached GST tax and saved. Tax Calculated but its seen that recoverable check box is not getting enabled.

2) As per note, created Claim Terms, created invoice, attached GST tax and during saving the invoice getting the below error:-

APP-JA-460204: Encountered the error in JAI_AP_TAX_PROCESS_PKG.Populate Stnd_Inv_Taxes: Tax determination error

ORA-01400: cannot insert NULL into AP_INVOICE_DISTRIBUTIONS_ALL.DIST_CODE_COMBINATION_ID

3) Then again i remove the Claim Terms for specific tax and then tried the steps. Invoice got saved and GST tax calculated but recoverable tax is disabled.